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Free BMI Calculator

Check your Body Mass Index instantly. Enter your height and weight to see if you fall into a healthy weight category.

Your Details

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kg

Your BMI Score

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UnderNormalOverObese

What is the BMI Calculator?

The BMI (Body Mass Index) Calculator is a simple health screening tool that uses a mathematical formula to estimate your total body fat based on your height and weight. It is widely used by doctors and health professionals to screen for weight categories that may lead to health problems.

What does it do?

  • Calculates your exact BMI score instantly.
  • Supports both Metric (cm/kg) and Imperial (ft/lbs) units.
  • Maps your score to standard WHO health categories.
  • Displays your status on a clear, visual gauge.

Who is it for?

  • Adults checking their general health status.
  • People tracking weight loss or fitness goals.
  • Health professionals screening patients.
  • Anyone curious about the medical definition of a "healthy weight".

How to use the BMI checker

How it Works

  1. 1

    Select Your Preferred Units

    Use the toggle switch at the top of the calculator to choose between Metric (centimeters and kilograms) or Imperial (feet/inches and pounds).
  2. 2

    Enter Height and Weight

    Type in your current height and weight into the designated input fields. The calculator will automatically update as you type.
  3. 3

    Check Your BMI Category

    Instantly view your calculated BMI score and see where you fall on the color-coded category gauge (Underweight, Normal, Overweight, or Obese).

Standard BMI Categories

Mathematical Formulas:

Metric: BMI = weight (kg) / [height (m)]²

Imperial: BMI = 703 × weight (lbs) / [height (in)]²

BMI Score RangeWeight Category
Below 18.5Underweight
18.5 – 24.9Normal Weight (Healthy)
25.0 – 29.9Overweight
30.0 and AboveObesity

Frequently Asked Questions

Frequently Asked Questions

Yes, our Body Mass Index Calculator is 100% free. We do not require any personal information, and we do not save your health data.
According to the World Health Organization (WHO), a normal, healthy BMI falls between 18.5 and 24.9.
The standard BMI formula provided here is designed for adults (age 20 and older). For children and teens, BMI is usually calculated differently and compared against age- and sex-specific percentiles.
BMI only uses height and weight; it cannot distinguish between fat and muscle. Because muscle is denser than fat, muscular athletes often have a higher body weight, which results in a high BMI, even if their body fat percentage is very low.

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